In the future, effective adaptation will be key to preventing food supply crises. For example, food production is projected to decline in tropical regions as rising temperatures decrease crop yields. Drought-prone areas of Africa are particularly vulnerable to food shortages due to a reduction in the land area suitable for agriculture. Agricultural losses could be severe in the Sahel, East Africa, and southern Africa. A study of some North African countries suggests that some rain-fed crop yields could decline as much as 50 percent in extreme years by 2020. Degradation of coral reefs and mangroves, as well as rising lake temperatures and overfishing, could decrease fish supplies in Africa.
If local temperature increases are limited to 1 to 3°C, some regions, such as Northern Europe and North America, could benefit from a longer growing season, more precipitation, and less frost, depending on the crop. However, these regions can also expect more flooding, which can reduce yields. If local temperatures rise beyond 1 to 3°C, crop yields are likely to decline as rising heat affects water availability and plant development. This illustrates the importance of reducing emissions enough to limit temperature increases to below this level.
A recent analysis looked at historical damage to food crops from high temperatures during the growing season alongside projections of future warming. It suggests that unprecedented heat during the growing season could threaten food security in many regions.
The United Nations recently projected that up to one quarter of global food production could be lost by 2050 due to the combined impact of climate change, land degradation, and water scarcity. At the same time, global population is projected to increase from the current 7 billion to about 9.5 billion people. The map shows projected regional changes in agricultural productivity due to climate change by 2080.